The allegations describe "Lord of the Flies" conditions that include threats and intimidation and activities with guards and supervisors in various stages of nudity at parties.
"We expect to see prompt and effective action taken as a result of these investigations," the spokesman, Ian C. Kelly, told reporters. Other possible actions include rebidding the contract or replacing individual guards and supervisors employed by the contractor, ArmorGroup North America, he said.
The State Department inspector general is leading the investigation of ArmorGroup. U.S. officials in Kabul also are conducting a review, Kelly said. And a team from the State Department's diplomatic security, management and contracting offices will go to Kabul to examine the situation.
ArmorGroup and the State Department came under fire Tuesday after an independent watchdog group said that the nearly 450 ArmorGroup guards live and work in an oppressive environment in which they are subjected to hazing and other inappropriate behavior by supervisors.
CBS News investigative correspondent Sharyl Attkisson reported Tuesday that in numerous e-mails, the guards, understaffing, sleep deprivation, "threats and intimidation." One guard refers to a group of guards and supervisors from the security contractor ArmorGroup as "sexual predators, deviants running rampant."
The situation has led to a breakdown in morale and leadership that compromises security at the embassy where nearly 1,000 U.S. diplomats, staff and Afghan nationals work, according to the Project on Government Oversight in Washington.
With insurgent attacks in Afghanistan increasing, any shortcomings in security put the diplomatic mission there at risk, the group said in a 10-page letter to Secretary of State Hillary Rodham Clinton.
More about the U.S. Embassy in Kabul, Afghanistan:
Shocking Hazing at U.S. Embassy in Kabul
Images of alleged hazing (Graphic Content)
Graphic Content: Additional video of Kabul hazing
Group: U.S. Embassy security in Kabul risky
Letter to Sec. Clinton describing abuses (.pdf)
The State Department has been aware of ArmorGroup's shortcomings, the letter said, but has failed to correct the problems. Instead, it has renewed the contract twice, with the most recent installment good through July 2010.
Kelly acknowledged that ArmorGroup has been notified eight times of poor performance since the original contract was awarded in March 2007.
Wackenhut Services, ArmorGroup North America's parent company, has not responded to requests for comment.
The Project on Government Oversight's findings are based on interviews with ArmorGroup guards, documents, photographs and e-mails that it said depict "Lord of the Flies" conditions. The reference is to the 1954 novel by William Golding about a group of British schoolboys who are stranded on a desert island and try, but fail, to govern themselves in a chaotic setting.
One e-mail from a guard describes lurid conditions at Camp Sullivan, the guards' quarters a few miles from the embassy. The message described scenes of abuse, including guards and supervisors urinating on people and "threats and intimidation from those leaders participating in this activity."
Photographs show guards and supervisors in various stages of nudity at parties that took place near the housing of other supervisors.
"There were some things going on in Kabul that we were not aware of, but we frankly should have been aware of," Kelly said.
ArmorGroup's management is aware of the conditions but has not stopped it or disciplined those responsible, the letter said. Two supervisors alleged to be the worst offenders have been allowed to resign and may now be working on other U.S. contracts, the group said.